1. Field of the Invention
The present invention relates to a liquid crystal display device, more particularly, to a multi-domain liquid crystal display device in which a common auxiliary electrode, a dielectric structure and/or an electric field induction window are formed around and/or within a pixel region to divide the pixel region into a plurality of domains, and a light-shielding layer is formed in a boundary region of the divided domains.
2. Discussion of the Related Art
Recently, a liquid crystal display device that drives a liquid crystal using an auxiliary electrode electrically insulated from a pixel electrode without aligning the liquid crystal has been suggested. Such a related art liquid crystal display device is described with reference to FIG. 1.
FIG. 1 is a sectional view of a unit pixel of the related art liquid crystal display device. The related art liquid crystal display device includes a first substrate, a second substrate, a plurality of data lines and gate lines and a thin film transistor. As shown in FIG. 1, the liquid crystal display device further includes a passivation film 37, a pixel electrode 13, and an auxiliary electrode 21. The data lines and gate lines are formed on the first substrate lengthwise and crosswise to divide the first substrate into a plurality of pixel regions. A thin film transistor is formed in each pixel region on the first substrate and includes a gate electrode, a gate insulating film, a semiconductor layer, an ohmic contact layer, and source/drain electrodes. The passivation film 37 is formed on the entire surface of the first substrate. The pixel electrode 13 is formed on passivation film 37 to be connected with the drain electrode. The auxiliary electrode 21 is formed on the gate insulating film to partially overlap the pixel electrode 13.
The related art liquid crystal display device further includes a light-shielding layer 25, a color filter layer 23 formed on the light-shielding layer 25, a common electrode 17 formed on the color filter layer 23, and a liquid crystal layer formed between the first substrate and the second substrate. The light-shielding layer 25 is formed on the second substrate to shield light leaked from the gate lines, the data lines, and the thin film transistor.
An open region or gap 27 may be formed in the common electrode 17 to distort electric field applied to the liquid crystal layer. The auxiliary electrode 21 formed around the pixel electrode 13 and the open region 27 of the common electrode 17, distort the electric field applied to the liquid crystal layer so that liquid crystal molecules are variously driven within a unit pixel. This is intended so that a dielectric energy by the distorted electric field places a liquid crystal director at a desired position when a voltage is applied to the liquid crystal display device. The liquid crystal display device requires the open region 27 or gap in the common electrode 17 to obtain multi-domain effect. To this end, a process for patterning the common electrode is additionally required.
Furthermore, if the open region 27 is not formed or has a small width, distortion range of the electric field required to divide the domain is weak. Accordingly, there is a problem at the time when the liquid crystal director reaches a stable state, it is relatively increased. Leakage of light occurs due to the open region, i.e., the boundary region between the domains, when displaying an image on a screen. For this reason, disclination occurs, thereby deteriorating contrast.
Accordingly, the present invention is directed to a multi-domain liquid crystal display device that substantially obviates one or more of the problems due to limitations and disadvantages of the related art.
An object of the present invention is to provide a multi-domain liquid crystal display device in which a common auxiliary electrode, a dielectric structure and/or an electric field induction window are formed around and/or within a pixel region to divide the pixel region into a plurality of domains, thereby improving a viewing angle.
Another object of the present invention is to provide a multi-domain liquid crystal display device in which a light-shielding layer is formed in a boundary region of divided domains to prevent leakage of light from occurring, thereby improving contrast.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the scheme particularly pointed out in the written description and claims hereof as well as the appended drawings.
A multi-domain liquid crystal display device of the present invention is an improvement over the device of Korean Patent Application No. 1999-05587, filed by the same applicant, in which a dielectric structure and/or an electric field induction window are formed around and/or within a pixel region to divide the pixel region into a plurality of domains, and a light-shielding layer is formed in a boundary region of the domains on an upper substrate and/or a lower substrate.
To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described, a multi-domain liquid crystal display device according to the present invention includes: first and second substrates; a plurality of gate lines formed on the first substrate in a first direction; a plurality of data lines formed in a second direction to cross the first direction; a plurality of thin film transistors formed in a portion where the gate lines cross the data lines; a plurality of pixel regions divided into at least one or more domains between neighboring gate and data lines; a plurality of pixel electrodes in each pixel region to be connected with the thin film transistors; at least one dielectric structure on the second substrate; a plurality of light-shielding layers formed in a boundary region of the domains and a region where the dielectric structure exists, on at least one of the first and second substrates; an alignment film on at least one of the first and second substrates; and a liquid crystal layer between the first substrate and the second substrate.
The multi-domain liquid crystal display device further includes at least one or more electric field induction windows within the pixel electrodes, and a common auxiliary electrode around each pixel region.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.